In 1914, Russia entered World War I in response to Austria-Hungary's declaration of war on Russia's ally Serbia. This was fought across multiple fronts while isolated from its allies. The Battle of Tannenberg, where the entire Russian Second Army was annihilated, cast an ominous shadow over the empire's future. The already-existing public distrust of the regime was deepened by the rising costs of the war and rumours of corruption. World War I takes Nicholas to the front. Back home, outrage grows over high casualties and Alexandra and Rasputin's political intrigues.

The French army stops the German advance at the battle of the Marne, while the Germans halt the Russians at Tannenberg on the eastern front. In France, the warring parties dig themselves in for 4 years in the trenches. Soldiers from the colonies come lend a hand to their colonizers and the war becomes global.